Why a Christian shouldnt get in a relationship with a non-christian...

To approach this issue i will use the Israeliltes and their journey through the old testament as an example( i guess there are many other ways to approach it...but because i did bibilical theology this sem...the OT was the first to come to mind) . Throughout the old testament from the time the ppl of israel left Egypt all the way through the end of the OT, it can be seen that thier life and thier relationship with God can be modelled as a sinosoid oscilating with respect to time(eg . the sine and cosine function....if still not sure what it is....basicly its just a function that oscilates up and down with a certain amplitude). So what is the reason for these massive fluctuations in thier relationship with God?? One very obvious reason is because of the influence of the surrounding nations on the israelites. From the beginning God has intended the ppl of Israel to be HIS ppl...a sanctified nation whose purpose is to glorify HIM. It is always the case that before the Israelites enter a new phase in thier life God always commands them not to have ny relations with the other neighbouring nations either politically or by marriage. For example before they went into Jericho...the command was to destroy everything and not to take anything. Someone did and he died because of it. Another example...before they crossed the river Jordan into the land of canaan God again commanded them to destroy everything, but they didnt, instead they made a political pact with the king of the amorites. The long term effect of this was the negative infuence these foreign nations had on the Israelites. The israelites start to worship other Gods, lead sinful lives ,want to be like the other nations etc. Another example is King Solomon. His reign as King of Israel started of well, and God blessed him with wisdom, wealth and many other stuff. But his reign started to decay when he allowed his foreign wives and concubines to influence him in particular the Egyptian one. He started to worship foreign Gods, and his focus was no more on God.
So after all these examples i guess it is pretty obvious why we shouldnt get into a relationship with a non-christian. So ....this might be hard to take but...i guess it boils down to where our priorities are....do we give God our highest priority or do we put ourselves higher than God? Do we want it our way or do we want God to have his way in our life?? How can we get into a relationship where the values and priorites are so different. You have a non-christian that doesnt go to church, doesnt care bout God and whos values are based so much on the world....and a Christian that is "suppose" to put God first in everything and whos values are based on GOds word. Well many people will say i will bring my other half to church and make them christian...but hey...bringing a person to church and hoping they will be christian just because it will make it legal for u to be with the person is clearly wrong...If the person does become Christian then God bless u ....but what if they dont. Your whole life could be screwed up.
Emotions is God given and is a beautiful thing. But if used in a wrong way, it will blind your mind and u can easily lose sight of GOD. God gave us a brain to use...so use it...blind emotions is useless...similarly knowledge without emotions is equally useless...Getting into a relationship without God is meaningless becuase the purpose of getting into the relationship(wutever it is) will not last...eg...the "in Love" feeling, nice , good looks, etc.. Love is more than that....love is a commitment...Think about it....y does the bible use the analogy of marriage to signify the relationship between Christ and the church? So u must be saying but thats marriage...i am not going to get married with her. So what is the point of getting into a relationship just to have fun and with no intention of having a long term relationship....wasting money, wasting time, wasting valuable brain capacity. Just because you have the potential to get into a relationship doesnt mean u must. U could use those resources to work on your relationship with God that is far more important than any relationship that u will be in in your life.